Tsai JC, Lin YH, Chen GT, Gao YK, Tseng YC, Kao CL, Chiou WH. Rhodium-Catalyzed Domino Hydroformylation/Double-Cyclization Reaction of Arylacetylenecarboxamides: Diastereoselectivity Studies and Application in the Synthesis of 1-Azabicyclo[x.y.0]alkanes.
Chem Asian J 2018;
13:3190-3197. [PMID:
30207086 DOI:
10.1002/asia.201801193]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/08/2018] [Indexed: 11/08/2022]
Abstract
A domino method for the rapid syntheses of 1-azabicyclo[x.y.0]alkane scaffolds, such as indolizidines, quinolizidines, decahydropyridoazepines, and their derivatives, has been developed. This strategy involved a rhodium-catalyzed hydroformylation of allyl-, 3-butenyl-, or homoallyl amides, followed by two spontaneous ring closures under mild conditions. The reaction scope and diastereoselectivity were fully explored by changing the substitution pattern on the amide and by altering the length of the carbon chain. This method was applied to the syntheses of natural alkaloids tashiromine and epilupinine. The clear differences between the reactivities of two isomeric amide substrates, 3-butenamide 1 j and homoallyl amide 1 i, could be attributed to better HOMO-LUMO overlap in the transition states that were derived from butenamides during cyclization. This explanation was supported by DFT calculations.
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